C++题解

#include <iostream>
#include <algorithm>
using namespace std;

int main(){
	int a;
	cin>>a;
	for (int i = 1; i <= a; ++i) {
		for (int j = a - i; j >= 1; --j) {
			cout << " ";
		}
		for (int j = i * 2 - 1; j >= 1; --j) {
			if (j == i * 2 - 1 || j == 1) {
				cout << "*";
			} else {
				cout << " ";
			}
		}
		cout << endl;
	}
	for (int i = a - 1; i >= 1; --i) {
		for (int j = a - i; j >= 1; --j) {
			cout << " ";
		}
		for (int j = i * 2 - 1; j >= 1; --j) {
			if (j == i * 2 - 1 || j == 1) {
				cout<<"*";
			} else {
				cout<<" ";
			}
		}
		cout << endl;
	}
	return 0;
}